Timing is important here, as you want to get the drama of two separate layers with gradation between. Let the first layer set partially but not completely--if you add the blackberry layer too soon, it will muddle your color; a bit too late, and it will slide right off the bottom layer.
1 1/2 cups vodka, divided
4 envelopes unflavored gelatin, divided
1 1/2 cups sugar, divided
1 cup fresh lemon juice
1 cup water, divided
8 cups blackberries
Lemon rind strips (optional)
How to Make It
Place 1 cup vodka in a medium bowl. Sprinkle 2 envelopes gelatin evenly over vodka; let stand 3 minutes. Combine 1 cup sugar, lemon juice, and 1/2 cup water in a medium saucepan over medium-high heat. Bring just to a boil, stirring until sugar dissolves. Add hot lemon juice mixture to vodka mixture, stirring until gelatin dissolves. Pour lemon-vodka mixture into an 8-inch square glass or ceramic baking dish coated with cooking spray; chill 1 hour and 45 minutes.
Place remaining 1/2 cup vodka in a medium bowl. Sprinkle remaining 2 envelopes gelatin evenly over vodka; let stand 3 minutes. Combine remaining 1/2 cup sugar, remaining 1/2 cup water, and 8 cups blackberries in a large saucepan; bring to a boil. Reduce heat; simmer 10 minutes, stirring mixture occasionally. Strain blackberry mixture through a fine sieve over a 4-cup glass measuring cup; discard solids. Add 2 cups hot blackberry mixture to vodka mixture, stirring until gelatin dissolves (reserve remaining blackberry mixture for another use). Gradually pour blackberry-vodka mixture evenly over partially set lemon-vodka mixture. Chill 3 hours or until set. Cut into 36 cubes. Garnish with blackberries and lemon rind strips, if desired.
Delicious! Did take a bit of work, especially making a double batch. My fridge timing was closer to 2:00 hours vs 1:45, but it was a 9x13 tray. Still got the beautiful layering. I used raspberries and the result was just as yummy and visually nice. Lemons - definitely use fresh squeezed. Vodka - go cheap since the juice and sugar will take care of that. Berries - fresh is great but go frozen if you can score it cheaper. Do keep the berry puree you strain from the juice. Stir into yogurt, oatmeal, a good muffin batter, whole grain pancake batter, scoop up with a hot buttermilk biscuit...
I used a pizza cutter and got cubes of different sizes. Next time I would try the trick with unflavored dental floss.
And I have my leftover lemon and raspberry simple syrups in the fridge for future use, most likely to make sangria.
You know, these turned out perfect and beautiful, but the work required just wasn't worth the payout. They were very sour, but still a hit. It was just so ridiculous to put so much effort into it. They are simply an elegant jello shot, not meant for an average get together. I won't bother making them again, but it was fun to see it work out.